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• Revert "avcodec/decode : copy the output parameters from the last bsf in the chain...

  12 septembre 2018, par James Almer

  Revert "avcodec/decode : copy the output parameters from the last bsf in the chain back to the AVCodecContext"
  This reverts commit f631c328e680a3dd491936b92f69970c20cdcfc7.
  The avcodec_parameters_to_context() call was freeing and reallocating
  
  AVCodecContext->extradata, essentially taking ownership of it, which according
  
  to the doxy is user owned. This is an API break and has produced crashes in
  
  some library users like Firefox[1].
  Revert until a better solution is found to internally propagate the filtered
  
  extradata back into the decoder context, or a decision is made to change the
  
  API.
  [1] https://bugzilla.mozilla.org/show_bug.cgi?id=1486080
  Signed-off-by : James Almer <jamrial@gmail.com>
  

  • [DH] libavcodec/decode.c

• ffprobe json output not working in exec, but works in CMD

  26 novembre 2015, par Nicholas Walker

  I’ve installed ffmpeg on my windows 2008 server.

  I use this string in CMD and i get what i want to get in my

  PHP file :

   ffprobe -v quiet -print_format json -show_format -show_streams "C:\wamp\www\uploads\fc30e528b500b26a391ed4f5ed484310.mp4" 

  This is my PHP function i found on another stackoverflow question, it had great feedback so i tested it.

  $file_name = 'fc30e528b500b26a391ed4f5ed484310';
  
  $file_ext = 'mp4';
  
  $ffprobe = 'C:\\ffmpeg\\bin\\ffprobe.exe';
  
  $videoFile = 'C:\\wamp\\www\\uploads\\'.$file_name.'.'.$file_ext;
  
  
  
  $cmd = shell_exec($ffprobe .' ffprobe -v quiet -print_format json -show_format -show_streams "'.$videoFile.'"');
  
  $parsed = json_decode($cmd, true);
  
  print_r($parsed);

  What is get back is nothing. I also tried using the same function i used with ffmpeg(which i got working for ffmpeg).

  $cmd = $ffprobe.' ffprobe -v quiet -print_format json -show_format -show_streams "'.$videoFile.'" 2>&1';
  
  echo shell_exec($cmd);

  This also brings back nothing.

  Any ideas ?

• convert char buffer (with pcm audio data) to short buffer

  15 décembre 2012, par testCoder

  I have char pAudioBuffer buffer which i got from function ffmpeg :

  int len = avcodec_decode_audio3(av_codec_context,
  
              (int16_t *) pAudioBuffer, &out_size, &packet);

  I know that audio format is two bytes per sample, i need to convert every two bytes to short value, i have tried to use code snippet below, but i often got zero instead of short value :

  int shortBufIndex = 0;
  
  for (int i = 0; i < (out_size); i += 2) {
  
      char b1 = pAudioBuffer[i];
  
      char b2 = pAudioBuffer[i + 1];
  
      short sample = atoi(&b1) + atoi(&b2);
  
      shortBuffer[shortBufIndex] = sample;
  
      shortBufIndex++;
  
      LOGI("BUFFER_ITEM='%d'", sample);
  
  }

  What i'm doing wrong, how to convert every two bytes in char buffer to short and and back.

  UPDATE :

  system's byte order is LITTLE_ENDIAN i have test it like this : Endianness of Android NDK

  How can i convert every two bytes in buffer to sample of short type and back. Please can you provide any code sample.